A former Obama administration national security official is aiming to challenge Rep. Tom MacArthur for New Jersey's 3rd Congressional District seat in 2018.

Democrat Andy Kim, who advised former President Barack Obama on fighting ISIS, announced via Twitter Monday that he will seek the Democratic nomination for the swing district seat.

"I’ve heard too many stories about people, many with pre-existing conditions, living with constant fear of losing their health care or being forced to pay skyrocketing premiums they can’t afford," Kim said in a release announcing his run. "The economic recovery has forgotten too many of our towns, replaced instead by persistent unemployment, a devastating opioid crisis and struggling communities still in need of help after superstorm Sandy."

MacArthur has drawn national headlines in recent weeks for helping to revive the House GOP health care bill by leading negotiations between conservative and moderate factions of the party. The bill passed the House last month and the Senate is drafting its own version.

Democrats have pounced on a Congressional Budget Office finding that found the House health care bill would leave 23 million more Americans without health insurance by 2026.

And after first embracing the House measure as a "great plan," Trump reportedly told Senate lawmakers behind closed doors that the House bill is “mean, mean, mean.” He added: “We need to be more generous, more kind.”

In a tweet announcing his run, Kim called MacArthur the "author" of the health care bill he called "TrumpCare 2.0."

Chris Russell, MacArthur's campaign spokesman, said MacArthur was "determined to confront and solve serious problems" like replacing Obamacare, which he said had caused skyrocketing insurance premiums.

"As for Andy Kim running on the healthcare issue, if he is as much of an 'expert' on healthcare as he was when advising President Obama on ISIS in Iraq, voters in Burlington and Ocean Counties would be wise to keep him on the JV Team," Russell said in an email, an allusion to Obama's 2014 reference to ISIS as a "JV team."

Kim, who grew up in Marlton and Cherry Hill, is a former Rhodes Scholar who also advised Gens. David Petraeus and John Allen in Afghanistan. He then served as the Iraq director on Obama's National Security Council, from 2013 to 2015, where he worked on the administration's efforts to fight ISIS.

The National Republican Congressional Committee, which aims to elect GOP members to the House, attacked Kim's record on ISIS highlighting the terror group's territorial gains in Iraq and Syria during his time as director.

"Under Andy Kim’s watch, the United States failed to grasp the threat ISIS presented to the world and failed to formulate a strategy to stop them," the group said in the statement.

Kim raised more than $50,000 as he considered a run for Congress, according to his fundraising website.